Organic light emitting display apparatus

ABSTRACT

An organic light emitting display apparatus includes an organic light emitting display panel including a display area having a transparent area and an opaque area, and a non-display area. A gate driver is configured to sequentially supply a gate pulse to a plurality of gate lines included in the organic light emitting display panel. An initialization circuit is configured to transfer gate pulses or initialization control signals, output from the gate driver, to a plurality of transparent area gate lines. A camera is configured to photograph a region in a forward direction with respect to the organic light emitting display panel, and the camera may be provided in the transparent area of a rear surface of the organic light emitting display panel. A first pixel driving circuit provided in the transparent area may differ from a second pixel driving circuit provided in the opaque area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No.10-2019-0173672 filed on Dec. 24, 2019, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND Technical Field

The present disclosure relates to an organic light emitting displayapparatus where a camera is mounted in a forward direction with respectto an organic light emitting display panel.

Description of the Related Art

As various kinds of applications are provided in electronic devices suchas smartphones, users desire display apparatuses including a widerdisplay unit.

Moreover, in electronic devices such as smartphones, a camera is mountedin a forward direction with respect to a display panel so that a userphotographs its own form while looking at its own form.

In this case, in order to maximally enlarge a width of a display areadisplaying an image in a display apparatus, a camera may be provided inthe display area.

However, in order to prevent a luminance deviation caused by thedegradation in each driving transistor, four or more transistors areincluded in each pixel of an organic light emitting display panel whichis a type of display panel. Therefore, even when a portion,corresponding to a camera, of the organic light emitting display panelis implemented as a transparent panel, a transmittance of light isreduced by transistors included in the transparent panel.

Due to this, the amount of light transferred to a camera is reduced,causing the degradation in quality of an image captured by the camera.

BRIEF SUMMARY

Accordingly, the present disclosure is directed to providing an organiclight emitting display apparatus that substantially obviates one or moreproblems due to limitations and disadvantages of the related art.

An aspect of the present disclosure is directed to providing an organiclight emitting display apparatus in which a first pixel driving circuitprovided in a transparent area, corresponding to a position of a camera,of a display area has a shape differing from that of a second pixeldriving circuit provided in an opaque area, except the transparent area,of the display area.

Additional advantages and features of the disclosure will be set forthin part in the description which follows and in part will becomeapparent to those having ordinary skill in the art upon examination ofthe following or may be learned from practice of the disclosure. Theobjectives and other advantages of the disclosure may be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the disclosure, as embodied and broadly described herein, there isprovided an organic light emitting display apparatus including anorganic light emitting display panel including a display area, includinga transparent area and an opaque area, and a non-display area, a gatedriver sequentially supplying a gate pulse to a plurality of gate linesincluded in the organic light emitting display panel, and aninitialization unit transferring gate pulses and/or initializationcontrol signals, output from the gate driver, to a plurality oftransparent area gate lines. A camera photographing a region in aforward direction with respect to the organic light emitting displaypanel may be provided in the transparent area of a rear surface of theorganic light emitting display panel, and a first pixel driving circuitprovided in the transparent area may differ from a second pixel drivingcircuit provided in the opaque area.

It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure areexemplary and explanatory and are intended to provide furtherexplanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiments of the disclosure andtogether with the description serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 is an exemplary diagram illustrating an external configuration ofan electronic device to which an organic light emitting displayapparatus according to an embodiment of the present disclosure isapplied;

FIG. 2 is an exemplary diagram illustrating an internal configuration ofan organic light emitting display apparatus according to an embodimentof the present disclosure;

FIG. 3 is an exemplary diagram illustrating a configuration of acontroller applied to an organic light emitting display apparatusaccording to an embodiment of the present disclosure;

FIG. 4 is an exemplary diagram illustrating a configuration of a gatedriver applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure;

FIG. 5 is an exemplary diagram illustrating a first pixel and a secondpixel each included in an organic light emitting display apparatusaccording to an embodiment of the present disclosure;

FIG. 6 is an exemplary diagram illustrating a structure of a first pixelapplied to an organic light emitting display apparatus according to anembodiment of the present disclosure;

FIG. 7 is a cross-sectional view illustrating a structure of a firstpixel applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure;

FIG. 8 is an exemplary diagram illustrating a structure of a secondpixel applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure;

FIG. 9 is an exemplary diagram illustrating a gate driver, aninitialization unit, and a transparent area each applied to an organiclight emitting display apparatus according to an embodiment of thepresent disclosure;

FIG. 10 is an exemplary diagram illustrating a structure where a firstpixel applied to the present disclosure is connected to a data line anda reference voltage supply line;

FIG. 11 is an exemplary diagram illustrating a structure of aninitialization unit applied to the present disclosure;

FIG. 12 is an exemplary diagram showing waveforms of signals applied toan initialization unit applied to the present disclosure;

FIG. 13 is an exemplary diagram showing waveforms of signals applied toan organic light emitting display apparatus according to an embodimentof the present disclosure;

FIGS. 14 to 16 are exemplary diagrams illustrating a driving method ofan organic light emitting display apparatus according to an embodimentof the present disclosure;

FIG. 17 is another exemplary diagram illustrating a first pixel and asecond pixel each included in an organic light emitting displayapparatus according to an embodiment of the present disclosure;

FIG. 18 is an exemplary diagram illustrating a gate driver, aninitialization unit, and a transparent area each applied to the organiclight emitting display apparatus illustrated in FIG. 17; and

FIGS. 19A and 19B are exemplary diagrams illustrating a result obtainedby comparing the compensation performance of a related art pixel drivingcircuit with the compensation performance of a first pixel drivingcircuit applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the exemplary embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Advantages and features of the present disclosure, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentdisclosure may, however, be embodied in different forms and should notbe construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present disclosureto those skilled in the art. Further, the present disclosure is onlydefined by scopes of claims.

A shape, a size, a ratio, an angle, and a number disclosed in thedrawings for describing embodiments of the present disclosure are merelyan example, and thus, the present disclosure is not limited to theillustrated details. Like reference numerals refer to like elementsthroughout. In the following description, when the detailed descriptionof the relevant known function or configuration is determined tounnecessarily obscure the important point of the present disclosure, thedetailed description will be omitted. In a case where ‘comprise’,‘have’, and ‘include’ described in the present specification are used,another part may be added unless ‘only˜’ is used. The terms of asingular form may include plural forms unless referred to the contrary.

In construing an element, the element is construed as including an errorrange although there is no explicit description.

In describing a position relationship, for example, when a positionrelation between two parts is described as ‘on˜’, ‘over˜’, ‘under˜’, and‘next˜’, one or more other parts may be disposed between the two partsunless ‘just’ or ‘direct’ is used.

In describing a time relationship, for example, when the temporal orderis described as ‘after˜’, ‘subsequent˜’, ‘next˜’, and ‘before˜’, a casewhich is not continuous may be included unless ‘just’ or ‘direct’ isused.

It will be understood that, although the terms “first”, “second”, etc.,may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

In describing the elements of the present disclosure, terms such asfirst, second, A, B, (a), (b), etc., may be used. Such terms are usedfor merely discriminating the corresponding elements from other elementsand the corresponding elements are not limited in their essence,sequence, or precedence by the terms. It will be understood that when anelement or layer is referred to as being “on” or “connected to” anotherelement or layer, it can be directly on or directly connected to theother element or layer, or intervening elements or layers may bepresent. Also, it should be understood that when one element is disposedon or under another element, this may denote a case where the elementsare disposed to directly contact each other, but may denote that theelements are disposed without directly contacting each other.

The term “at least one” should be understood as including any and allcombinations of one or more of the associated listed elements. Forexample, the meaning of “at least one of a first element, a secondelement, and a third element” denotes the combination of all elementsproposed from two or more of the first element, the second element, andthe third element as well as the first element, the second element, orthe third element.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings.

FIG. 1 is an exemplary diagram illustrating an external configuration ofan electronic device to which an organic light emitting displayapparatus according to an embodiment of the present disclosure isapplied.

The organic light emitting display apparatus according to an embodimentof the present disclosure may configure an electronic device. Theelectronic device may include, for example, a smartphone, a tabletpersonal computer (PC), a television (TV), a monitor, etc. In FIG. 1, asmartphone is illustrated as an example of the electronic device. In thefollowing description, an example where the electronic device is asmartphone will be described.

FIG. 2 is an exemplary diagram illustrating an internal configuration ofan organic light emitting display apparatus according to an embodimentof the present disclosure, FIG. 3 is an exemplary diagram illustrating aconfiguration of a controller applied to an organic light emittingdisplay apparatus according to an embodiment of the present disclosure,and FIG. 4 is an exemplary diagram illustrating a configuration of agate driver applied to an organic light emitting display apparatusaccording to an embodiment of the present disclosure.

The electronic device, as illustrated in FIGS. 1 and 2, may include anorganic light emitting display apparatus 10 according to the presentdisclosure and an external case 20 which supports the organic lightemitting display apparatus 10.

The organic light emitting display apparatus according to an embodimentof the present disclosure, as illustrated in FIGS. 1 to 4, may include adisplay area AA displaying an image and a non-display area NAA providedoutside the display area AA. The display area AA may include an organiclight emitting display panel 100 including a transparent area AA1 whichtransmits light and an opaque area AA2 which does not transmit light, acamera 600 which is provided in the transparent area AA1 in a rearsurface of the organic light emitting display panel 100 and photographsa region in a forward direction with respect to the organic lightemitting display panel 100, a gate driver 200 which sequentiallysupplies a gate pulse to a plurality of gate lines GL1 to TGLg includedin the organic light emitting display panel 100, a data driver 300 whichsupplies data voltages to a plurality of data lines DL1 to DLd includedin the organic light emitting display panel 100, an initializationcircuit 500 (which may be referred to herein as an initialization unit500) which transfers gate pulses, output from the gate driver 200, to aplurality of transparent area gate lines TGLg-4 to TGLg included in thetransparent area AA1 among the plurality of gate lines GL1 to TGLg ortransfers, to the transparent area gate lines TGLg-4 to TGLg,initialization control signals for initializing first pixel drivingcircuits provided in the transparent area AA1, and a controller 400which controls driving of the gate driver 200, the initialization unit500, and the data driver 300. The first pixel driving circuit providedin the transparent area AA1 and the second pixel driving circuitprovided in the opaque area AA2 may have different structures, andparticularly, the number of transistors included in the first pixeldriving circuit may be set to be less than the number of transistorsincluded in the second pixel driving circuit. The initialization unit500 may include any circuitry suitable to perform the various operationsdescribed herein with respect to the initialization unit 500.

The camera 600 may be provided between the external case 20 and theorganic light emitting display panel 100 and may be driven based oncontrol by the controller 400 or control by an external system 800 whichcontrols driving of the electronic device. The camera 600 may beprovided in the rear surface of the organic light emitting display panel100 and may perform a function of photographing a region in a forwarddirection with respect to the organic light emitting display panel 100.Here, the forward direction with respect to the organic light emittingdisplay panel 100 may denote a direction in which the organic lightemitting display panel 100 displays an image.

The controller 400, as illustrated in FIG. 3, may include a data aligner430 which realigns input video data Ri, Gi, and Bi transferred from theexternal system 800 by using a timing synchronization signal TSStransferred from the external system 800 to generate image data Data andsupplies the image data Data to the data driver 300, a control signalgenerator 420 which generates a gate control signal GCS and a datacontrol signal DCS by using the timing synchronization signal TSS, aninput unit 410 which receives the timing synchronization signal TSS andthe input video data Ri, Gi, and Bi from the external system 800,transfers the input video data Ri, Gi, and Bi to the data aligner 430,and transfers the timing synchronization signal TSS to the controlsignal generator 420, and an output unit 440 which outputs the imagedata Data generated by the data aligner 430 to the data driver 300,transfers the data control signal DCS generated by the control signalgenerator 420 to the data driver 300, and transfers the gate controlsignal GCS generated by the control signal generator 420 to the gatedriver 200. The control signal generator 420 may generate a firstturn-on control signal ALL_L for controlling the initialization unit 500by using the timing synchronization signal TSS. However, the presentembodiment is not limited thereto, and in other embodiments, the firstturn-on control signal ALL_L may be generated by the gate driver 200.

The gate driver 200 may be configured as an integrated circuit (IC), andthen, may be mounted in the non-display area NAA or may be directlyembedded into the non-display area NAA.

The gate driver 200, as illustrated in FIG. 4, may include first tog^(th) stages ST1 to STg.

Each of the first to g^(th) stages ST1 to STg may generate a gate signalVG and an emission signal EM, output the gate signal to a gate line GL,and output the emission signal EM to an emission line.

For example, the first stage ST1 driven by a gate start signaltransferred from the controller 400 may generate a first gate signal VG1by using at least one gate clock transferred from the controller 400 andmay output the first gate signal VG1 to a first gate line GL1. Also, thefirst stage ST1 may be driven by an emission start signal transferredfrom the controller 400 to generate a first emission signal EM1 by usingat least one emission clock transferred from the controller 400 and mayoutput the first emission signal EM1 to a first emission line which isarranged in parallel with the first gate line GL1.

In this case, the first gate signal VG1 and the first emission signalEM1 may drive the second stage ST2, and thus, the second stage ST2 maygenerate a second gate signal VG2 and a second emission signal EM2 andmay respectively output the second gate signal VG2 and the secondemission signal EM2 to a second gate line GL2 and a second emission linewhich is arranged in parallel with the second gate line GL2.

Moreover, the g-1 ^(th) gate signal VGg-1 and the g-1 ^(th) emissionsignal EMg-1 each output from the g-1 ^(th) stage STg-1 may drive theg^(th) stage STg. Therefore, the g^(th) stage STg may generate a g^(th)gate signal VGg and a g^(th) emission signal EMg and may respectivelyoutput the g^(th) gate signal VGg and the g^(th) emission signal EMg toa g^(th) gate line GLg and a g^(th) emission line which is arranged inparallel with the g^(th) gate line GLg.

In this case, in the present disclosure, an order in which the first tog^(th) gate signals VG1 to VGg and the first to g^(th) emission signalsEM1 to EMg are output is not limited to the above-described order.Therefore, in the present disclosure, an order in which the first tog^(th) gate signals VG1 to VGg and the first to g^(th) emission signalsEM1 to EMg are output may be variously changed.

Moreover, a structure of each of the stages ST1 to STg for outputtingthe first to g^(th) gate signals VG1 to VGg and the first to g^(th)emission signals EM1 to EMg may be variously designed by using stagesfor generating gate signals and emission signals, which are being usedcurrently and generally. That is, the structure of each of the stagesST1 to STg may be implemented as various types by using structures ofstages which are being used currently.

To provide an additional description, the feature of the presentdisclosure may be a feature where a structure of each of the stages ST1to STg for generating the gate signals VG1 to VGg and the emissionsignals EM1 to EMg on the basis of the above-described order isimplemented as various types by those skilled in the art, instead of astructure of each of the stages ST1 to STg for generating the gatesignals VG1 to VGg and the emission signals EM1 to EMg.

The data driver 300 may be equipped in a chip-on film attached on theorganic light emitting display panel 100. The chip-on film may beconnected to a main board including the controller 400. However, thedata driver 300 may be directly mounted on the organic light emittingdisplay panel 100 and may be electrically connected to the main board.The data driver 300 may convert the image data Data, transferred fromthe controller 400, into data voltages and may output the data voltagesto the data lines DL1 to DLd.

The external system 800 may perform a function of driving the controller400 and the electronic device. That is, when the electronic device is asmartphone, the external system 800 may receive various voiceinformation, video information, and letter information over a wirelesscommunication network and may transfer the video information to thecontroller 400. In the following description, the video informationtransferred from the external system 800 to the controller 400 may bereferred to as input video data. Also, the external system 800 mayexecute an application for controlling the camera 600. The applicationmay be downloaded to the external system 800 as an application (App)type, and then, may be executed by the external system 800.

The organic light emitting display panel 100 may include a plurality ofpixels 110 which each include an organic light emitting diode (OLED) anda pixel driving circuit for driving the OLED. Also, the organic lightemitting display panel 100 may include a plurality of signal lines whichdefine a pixel area, where the pixels 110 are provided, and supply adriving signal to the pixel driving circuit. The signal lines mayinclude various kinds of lines, in addition to the gate lines GL1 toTGLg and the data lines DL1 to DLd.

In the following description, gate lines provided in the transparentarea AA1 among the gate lines GL1 to TGLg may be referred to astransparent area gate lines, and gate lines provided in the opaque areaAA2 among the gate lines GL1 to TGLg may be referred to as opaque areagate lines. The transparent area gate lines may be referred to byreference numeral TGL, and the opaque area gate lines may be referred toby reference numeral GL. That is, a transparent area gate line amonggate lines referred to by reference numeral GL may be referred to byreference numeral TGL.

For example, in the organic light emitting display apparatus illustratedin FIG. 2, first to g-5 ^(th) gate lines GL1 to GLg-5 may be referred toas opaque area gate lines, and g-4 ^(th) to g gate lines TGLg-4 to TGLgmay be referred to as transparent area gate lines.

Moreover, pixels provided in the transparent area among the pixels 110may be referred to as first pixels, and pixels provided in the opaquearea among the pixels 110 may be referred to as second pixels.

In this case, each of the first pixels may include a first pixel drivingcircuit and a first OLED, and each of the second pixels may include asecond pixel driving circuit and a second OLED.

The organic light emitting display panel 100, as illustrated in FIGS. 1and 2, may include the display area AA displaying an image and thenon-display area NAA provided outside the display area AA.

The display area AA may include a transparent area AA1 which transmitslight and an opaque area AA2 which does not transmit light. The camera600, which photographs a region in the forward direction with respect tothe organic light emitting display panel 100, may be disposed at aportion, corresponding to the transparent area AA1, of the rear surfaceof the organic light emitting display panel 100.

The transparent area AA1 may be implemented to be transparent so thatexternal light travels to the inside of the camera 600.

The opaque area AA2 may not need to transmit external light, and thus,may be implemented to be opaque. However, the opaque area AA2 may alsobe implemented to be transparent.

The non-display area NAA may be provided outside the display area AA.

A width of the non-display area NAA may be formed to be very small, andthen, when the most of the non-display area NAA is covered by theexternal case 20, only the display area AA may be exposed at a frontsurface of the electronic device as illustrated in FIG. 1.

Each of the first pixels provided in the transparent area AA1 mayinclude the first pixel driving circuit including three transistors anda first OLED connected to the first pixel driving circuit, forperforming internal compensation.

Each of the second pixels provided in the opaque area AA2 may includethe second pixel driving circuit including at least four transistors anda second OLED connected to the second pixel driving circuit, forperforming internal compensation.

A detailed configuration of each of the first and second pixels will bedescribed below in detail with reference to FIGS. 5 to 8.

FIG. 5 is an exemplary diagram illustrating a first pixel and a secondpixel each included in an organic light emitting display apparatusaccording to an embodiment of the present disclosure, FIG. 6 is anexemplary diagram illustrating a structure of a first pixel applied toan organic light emitting display apparatus according to an embodimentof the present disclosure, FIG. 7 is a cross-sectional view illustratinga structure of a first pixel applied to an organic light emittingdisplay apparatus according to an embodiment of the present disclosure,and FIG. 8 is an exemplary diagram illustrating a structure of a secondpixel applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure.

The display area AA of the organic light emitting display panel 100 mayinclude a plurality of pixels 110 which includes an organic lightemitting diode OLED and a pixel driving circuit PDC for driving theorganic light emitting diode OLED. As described above, pixels providedin the transparent area AA1 among the pixels 110 may be referred to asfirst pixels 110 a, and pixels provided in the opaque area AA2 among thepixels 110 may be referred to as second pixels 110 b. In this case, eachof the first pixels 110 a may include a first pixel driving circuit PDC1and a first organic light emitting diode OLED1 as illustrated in FIG. 6,and each of the second pixels 110 b may include a second pixel drivingcircuit PDC2 and a second organic light emitting diode OLED2 asillustrated in FIG. 8.

Moreover, the organic light emitting display panel 100 may include aplurality of signal lines which define a plurality of pixel areas, wherethe pixels 110 are respectively provided, and supply a driving signal tothe pixel driving circuit PDC.

Hereinafter, the signal lines applied to the first pixel 110 a and thesecond pixel 110 b will be described first, a structure of the firstpixel 110 a will be described with reference to FIGS. 6 and 7, and astructure of the second pixel 110 b will be described with reference toFIG. 8.

First, the signal lines may include a gate line GL, a data line DL, asensing pulse line SPL, a sensing line SL, a first driving voltage linePLA, a second driving voltage line PLB, an emission line EL, a referencevoltage supply line, and a transfer line TL through which a referencevoltage or a data voltage is supplied.

A plurality of gate lines GL, as illustrated in FIG. 2, may be arrangedat certain intervals in a second direction (for example, a widthwisedirection) of the organic light emitting display panel 100. A gate lineincluded in the first pixel 110 a illustrated in FIG. 6 may be referredto as a transparent area gate line TGL.

A plurality of sensing pulse lines SPL, as illustrated in FIG. 8, may bearranged at certain intervals in parallel with the gate lines GL.

A plurality of data lines DL, as illustrated in FIGS. 2, 6, and 8, maybe arranged at certain intervals in a first direction (for example, alengthwise direction) of the organic light emitting display panel 100 tointersect with the gate lines GL and the sensing pulse lines SPL.

A plurality of sensing lines SL, as illustrated in FIG. 8, may bearranged at certain intervals in parallel with the data lines DL.

The first driving voltage line PLA, as illustrated in FIGS. 6 and 8, maybe provided apart from the data line DL and the sensing line SL by acertain interval in parallel with the data line DL and the sensing lineSL. The first driving voltage line PLA may be connected to the gatedriver 200 or a power supply 700 illustrated in FIG. 2 and may transfera first driving voltage ELVDD, supplied from the power supply 700, toeach pixel 110.

The second driving voltage line PLB, as illustrated in FIGS. 6 and 8,may transfer a second driving voltage ELVSS, supplied from the powersupply unit 700, to each of the pixels 110.

The emission lines EL, as illustrated in FIGS. 6 and 8, may be arrangedin parallel with the gate lines GL. The emission lines EL may supply anemission signal EM, transferred from the gate driver 200, to each pixel110.

A reference voltage, which is to be supplied to each of the first pixels110 a, may be supplied to the reference voltage supply line. Thereference voltage may be supplied from the power supply 700.

The transfer line TL, as illustrated in FIG. 6, may be connected to thefirst pixel 110 a. The transfer line TL may supply the first pixel 110 awith the reference voltage supplied through the reference voltage supplyline or a data voltage supplied through the data line DL.

A plurality of first pixels 110 a may be provided in the transparentarea AA1, and each of the first pixels 110 a, as illustrated in FIG. 6,may include a first pixel driving circuit PDC1 and a first organic lightemitting diode OLED1.

The first pixel driving circuit PDC1 may include a capacitor CSTincluding a first terminal connected to the transfer line TL throughwhich the reference voltage or a data voltage Vdata is transferred, adriving transistor DR including a first terminal connected to the firstdriving voltage line PLA and a gate connected to a second terminal ofthe capacitor CST, a first transistor SW1 including a first terminalconnected to the gate of the driving transistor DR, a second terminalconnected to the second terminal of the driving transistor DR, and agate connected to the transparent area gate line TGL, and a secondtransistor SW2 including a first terminal connected to the secondterminal of the driving transistor DR, a second terminal connected tothe first organic light emitting diode OLED1, and a gate connected to anemission control line EL.

A detailed driving method of the pixel driving circuit PDC1 will bedescribed below in detail with reference to FIGS. 9 to 16.

A cross-sectional structure of the first pixel 110 a including the firstpixel driving circuit PDC1 is illustrated in FIG. 7. FIG. 7 illustratesa cross-sectional surface taken along line A-A′ illustrated in thetransparent area of FIG. 5. In the cross-sectional structure of thefirst pixel 110 a illustrated in FIG. 7, each of layers other thanbelow-described portions may include an organic material, an inorganicmaterial, or a mixture layer thereof and may perform a function of aninsulator or a planarization layer.

A plurality of metal lines included in the first pixel 110 a may beformed of transparent metal such as indium tin oxide (ITO).

The first organic light emitting diode OLED1 may include an anode 20, alight emitting layer 30, and a cathode 40. The cathode 40 may be formedof transparent metal. The anode 20 may be formed of a double layerincluding transparent metal 21 and silver (Ag) 22, but the silver 22 maybe omitted for enhancing a transmittance.

The capacitor CST may include metal included in each of the data line DLand the first driving voltage line PLA and metal included in each of thefirst transistor SW1, the second transistor SW2, and a gate of thedriving transistor DR.

Various organic materials (for example, a material included in a bank, amaterial included in an insulation layer, and a material included in aplanarization layer) included in the first pixel 110 a may be formed ofa transparent material.

As described above, since the number of transistors included in thefirst pixel driving circuit PDC1 is three, a region X, where the firstpixel driving circuit PDC1 is disposed, of the first pixel 110 a maydecrease, and thus, a size of a transparent portion of the first pixel110 a may relatively increase.

Moreover, the number of transistors included in the first pixel drivingcircuit PDC1 may be small and the region X with the first pixel drivingcircuit PDC1 disposed therein may include a transparent material, andthus, a transmittance of the region X with the first pixel drivingcircuit PDC1 disposed therein may more increase than that of a regionwith the second pixel driving circuit PDC2 disposed therein

Therefore, comparing with the second pixel 110 b, a transmittance of thefirst pixel 110 a may increase, and thus, the amount of lighttransferred to the camera 600 through the first pixel 110 a mayincrease.

In this case, a density (pixel per inch (PPI)) of the first pixels 110 aincluded in the transparent area AA1 may be set to be equal to a density(PPI) of the second pixels 110 b included in the opaque area AA2.

Finally, the second pixels 110 b may be provided in the opaque area AA2,and as illustrated in FIG. 8, each of the second pixels 110 b mayinclude a second pixel driving circuit PDC2 and a second organic lightemitting diode OLED2.

The second pixel driving circuit PDC2 may include at least fourtransistors, for performing internal compensation. That is, the number(four or more) of transistors included in the second pixel drivingcircuit PDC2 may be set to be greater than the number (three) oftransistors included in the first pixel driving circuit PDC1.

For example, as illustrated in FIG. 8, the second pixel driving circuitPDC2 may include a driving transistor Tdr which controls the amount ofcurrent flowing in the second organic light emitting diode OLED2, aswitching transistor Tsw1 which includes a first terminal connected tothe data line DL, a second terminal connected to a gate of the drivingtransistor Tdr, and a gate connected to the gate line GL, an emissiontransistor Tsw3 which includes a first terminal connected to the firstdriving voltage line PLA, a second terminal connected to the firstterminal of the driving transistor Tdr, and a gate connected to theemission line EL, for controlling a current flowing to the drivingtransistor Tdr, a storage capacitor STC which is connected to the secondterminal of the emission transistor Tsw3 and the gate of the drivingtransistor Tdr, and a sensing transistor Tsw2 which includes a firstterminal connected to the second terminal of the driving transistor Tdr,a second terminal connected to a sensing line SL, and a gate connectedto a sensing pulse line SPL.

A current supplied to the second organic light emitting diode OLED2through the second pixel driving circuit PDC2 may be proportional to thesquare ((Vgs−Vth)²) of a difference voltage between a gate-sourcevoltage Vgs of the driving transistor Tdr and a threshold voltage Vth ofthe driving transistor Tdr.

In this case, the second pixel driving circuit PDC2 may use signalshaving various forms so as to remove the threshold voltage Vth from thesquare ((Vgs-Vth)²) of the difference voltage.

When the threshold voltage Vth is removed from the square ((Vgs−Vth)²)of the difference voltage, a current supplied to the second organiclight emitting diode OLED2 may be maintained to be constant regardlessof the threshold voltage Vth.

That is, even when the threshold voltage of the driving transistor Tdrincluded in the second pixel 110 b is shifted because the organic lightemitting display panel 100 is used for a long time, the second pixeldriving circuit PDC2 may remove the threshold voltage Vth from thesquare ((Vgs−Vth)²) of the difference voltage, a current correspondingto a data voltage Vdata may flow to the second organic light emittingdiode OLED2.

To provide an additional description, the second pixel driving circuitPDC2 may perform a function of allowing a current corresponding to thedata voltage Vdata to flow to the second organic light emitting diodeOLED2, regardless of a shift of the threshold voltage of the drivingtransistor Tdr, and such a function may be referred to as internalcompensation. The second pixel driving circuit PDC2 may be configured asvarious types including at least four transistors so as to performinternal compensation, and a driving method of the second pixel drivingcircuit PDC2 may be variously modified.

FIG. 9 is an exemplary diagram illustrating a gate driver, aninitialization unit, and a transparent area each applied to an organiclight emitting display apparatus according to an embodiment of thepresent disclosure, FIG. 10 is an exemplary diagram illustrating astructure where a first pixel applied to the present disclosure isconnected to a data line and a reference voltage supply line, FIG. 11 isan exemplary diagram illustrating a structure of an initialization unitapplied to the present disclosure, and FIG. 12 is an exemplary diagramshowing waveforms of signals applied to an initialization unit appliedto the present disclosure. In FIG. 9, gate pulses supplied to the firstpixel 110 a and the second pixel 110 b are illustrated.

As described above, the organic light emitting display apparatusaccording to an embodiment of the present disclosure may include theorganic light emitting display panel 100 including the first pixels 110a and the second pixels 110 b, the gate driver 200, the data driver 300,the initialization unit 500, and the controller 400.

The transparent area AA1, as illustrated in FIGS. 2 and 5, may be formedfrom one end of the display area AA to the other end of the display areaAA. For example, as illustrated in FIGS. 2 and 5, the transparent areaAA1 may be provided between a first non-display area NAA1 including thegate driver 200 and a second non-display area NAA2 facing the firstnon-display area NAA1 in the non-display area NAA.

In this case, the initialization unit 500 may be provided in the firstnon-display area NAA1 along with the gate driver 200, or may be includedin the gate driver 200. When the initialization unit 500 is separatedfrom the gate driver 200, the initialization unit 500 may be providedbetween the gate driver 200 and the transparent area AA1.

The initialization unit 500, as illustrated in FIGS. 9 to 11, maytransfer gate pulses SCANg-3 to SCANg, output from the gate driver 200,to transparent area gate lines TGL provided in the transparent area AA1among the plurality of gate lines or may transfer, to the transparentarea gate lines TGL, initialization control signals VGL for initializingthe first pixel driving circuits provided in the transparent area AA1.

To this end, the initialization unit 500 may include a plurality offirst initialization drivers 510 connected to the transparent area gatelines TGL.

Each of the first initialization drivers 510, as illustrated in FIG. 11,may include a first initialization transistor Tini1, which includes afirst terminal connected to an initialization control signal supply lineISL, a second terminal connected to the transparent area gate line TGL,and a gate connected to a first turn-on control line TCL1, and a secondinitialization transistor Tini2 which includes a first terminalconnected to a transparent area gate output line TGOL of the gate driver200, a second terminal connected to the transparent area gate line TGL,and a gate connected to a second turn-on control line TCL2.

In this case, as illustrated in FIG. 12, a phase of a first turn-oncontrol signal ALL_L supplied through the first turn-on control lineTCL1 may be set to be opposite to a phase of a second turn-on controlsignal EN_SN supplied through the second turn-on control line TCL2.

The first turn-on control signal ALL_L and the second turn-on controlsignal EN_SN may be generated by the controller 400, or may be generatedby the gate driver 200 on the basis of the gate control signal GCS.

The initialization control signal VGL supplied through theinitialization control signal supply line ISL may have a voltage forturning on the first transistor SW1.

For example, as illustrated in FIG. 10, when the first transistor SW1 isformed as a P-type transistor, the initialization control signal VGL maybe a low voltage.

The initialization control signal VGL may be generated by the controller400, or may be generated by the gate driver 200 on the basis of the gatecontrol signal GCS.

Referring to FIGS. 11 and 12, when the first turn-on control signalALL_L is logic low and the second turn-on control signal EN_SN is logichigh, the first initialization driver 510 may output the initializationcontrol signal VGL (i.e., a low voltage), and when the first turn-oncontrol signal ALL_L is logic high and the second turn-on control signalEN_SN is logic low, the first initialization driver 510 may output thegate signal GL.

For example, when the first turn-on control signal ALL_L is logic lowand the second turn-on control signal EN_SN is logic high, the firstinitialization transistor Tini1 may be turned on and the secondinitialization transistor Tini2 may be turned off. Therefore, theinitialization control signal VGL (i.e., a low voltage) may betransferred to the transparent area gate line TGL through the firstinitialization transistor Tini1.

Moreover, when the first turn-on control signal ALL_L is logic high andthe second turn-on control signal EN_SN is logic low, the firstinitialization transistor Tini1 may be turned off and the secondinitialization transistor Tini2 may be turned on. Therefore, the gatesignal GL may be transferred to the transparent area gate line TGLthrough the second initialization transistor Tini2.

The gate signal VG may include a signal (hereinafter simply referred toas a gate pulse SCAN) for turning on the first transistor SW1 and asignal (hereinafter simply referred to as a gate-off signal Voff) forturning off the first transistor SW1.

To provide an additional description, as illustrated in FIGS. 9 and 12,in one frame period where the organic light emitting display paneldisplays one image, the initialization control signals VGL having a lowvoltage may be simultaneously transferred to the transparent area gatelines TGL and the first pixels 110 a provided in the transparent areaAA1 may be initialized by the initialization control signals VGL, in aperiod where one gate pulse is output.

As described above, the gate signal VG or the initialization controlsignal VGL may be supplied to the transparent area gate line TGL. Thegate signal VG may include the gate pulse SCAN and the gate-off signalVoff.

A generic name for the gate signal VG or the initialization controlsignal VGL supplied to the transparent area gate line TGL may be atransparent area gate signal TGS. The transparent area gate signal TGS,as illustrated in FIG. 9, may include the initialization control signalVGL, the gate-off signal Voff, and the gate pulse SCAN.

A first terminal of the capacitor CST included in the first pixeldriving circuit PDC1, as illustrated in FIGS. 9 and 10, may be connectedto a reference voltage control transistor Trc and a data voltage controltransistor Tdc.

A first terminal of the reference voltage control transistor Trc may beconnected to a reference voltage supply line RVL through which areference voltage VREF is supplied, a second terminal thereof may beconnected to the first terminal of the capacitor CST, and a gate thereofmay be connected to an emission line EL through which an emission signalEM is supplied.

A first terminal of the data voltage control transistor Tdc may beconnected to the first terminal of the capacitor CST, a second terminalthereof may be connected to the data driver 300, and a gate thereof maybe connected to a data control line DCL through which a data controlsignal DATA_EN is supplied.

A data extension line DEL provided between the second terminal of thereference voltage control transistor Trc and the first terminal of thedata voltage control transistor Tdc may be connected to a plurality oftransfer lines TL which are connected to first pixels 110 a providedalong data extension lines DEL.

A data line DL provided between the data voltage control transistor Tdcand the data driver 300 may be connected to a plurality of opaque areagate lines GL which are connected to second pixels 110 b provided alongthe data line DL.

Hereinafter, a method of performing internal compensation by using thefirst pixel driving circuit PDC1 will be described with reference toFIGS. 1 to 16.

FIG. 13 is an exemplary diagram showing waveforms of signals applied toan organic light emitting display apparatus according to an embodimentof the present disclosure, and FIGS. 14 to 16 are exemplary diagramsillustrating a driving method of an organic light emitting displayapparatus according to an embodiment of the present disclosure.

First, as illustrated in FIGS. 12 to 14, in a first period F1, thetransparent area gate signals TGS having a low level may be supplied tothe transparent area gate lines TGL. The transparent area gate signalsTGS having a low level may be supplied to gates of the first transistorsSW1 included in the first pixel driving circuits PDC1. Therefore, thefirst transistors SW1 may be turned on. The supply of the transparentarea gate signals TGS having a low level to the transparent area gatelines TGL may denote that the first initialization transistor Tini1illustrated in FIG. 11 are turned on by the first turn-on control signalALL_L, and thus, the initialization control signal VGL having a lowlevel is supplied to the transparent area gate line TGL.

In this case, the first driving voltage ELVDD may also have a low level,and thus, the driving transistor DR may also be turned on. A low levelof the first driving voltage ELVDD may be equal to or less than thesecond driving voltage ELVSS.

The data control signal DATA_EN may have a high level and the emissionsignal EM may have a low level, and thus, the data voltage controltransistor Tdc may be turned off and the reference voltage controltransistor Trc may be turned on. Therefore, a reference voltage VREF maybe supplied to the first terminal of the capacitor CST through thereference voltage control transistor Trc. A reference voltage VREF_(H)supplied through the reference voltage supply line RVL and the datavoltage control transistor Tdc may have a high level.

Since the emission signal EM has a low level, the second transistor SW2may also be turned on.

Therefore, a difference voltage (=ELVDD_(L)−VREF_(H)) between the firstdriving voltage ELVDD_(L) and the reference voltage VREF may be chargedinto the capacitor CST, a voltage V_(G) at the gate of the drivingtransistor DR may be the first driving voltage ELVDD_(L), and a voltageV_(S) at a source of the driving transistor DR may be the first drivingvoltage ELVDD_(L).

Therefore, in the first period F1, the gate and the source of thedriving transistor DR and the first organic light emitting diode OLED1may be initialized to the first driving voltage ELVDD_(L).

Subsequently, as illustrated in FIGS. 12, 13, and 15, in a second periodF2, the transparent area gate signals TGS having a low level may besupplied to the transparent area gate lines TGL. The transparent areagate signals TGS having a low level may be supplied to gates of thefirst transistors SW1 included in the first pixel driving circuits PDC1.Therefore, the first transistors SW1 may be turned on. The supply of thetransparent area gate signals TGS having a low level to the transparentarea gate lines TGL may denote that the second initialization transistorTini2 illustrated in FIG. 11 are turned on by the second turn-on controlsignal EN_SN, and thus, the gate pulse SCAN having a low level issupplied to the transparent area gate line TGL.

In this case, the first driving voltage ELVDD may have a high level.

The data control signal DATA_EN may have a low level and the emissionsignal EM may have a high level, and thus, the data voltage controltransistor Tdc may be turned on and the reference voltage controltransistor Trc may be turned off. Therefore, a data voltage Vdata may besupplied to the first terminal of the capacitor CST through the datavoltage control transistor Tdc.

Since the emission signal EM has a high level, the second transistor SW2may be turned off.

Therefore, a voltage (=ELVDD_(H)−|Vth|−Vdata) calculated by subtractingan absolute value of the threshold voltage Vth of the driving transistorDR and the data voltage Vdata from the first driving voltage ELVDD_(H)may be charged into the capacitor CST, the voltage V_(G) at the gate ofthe driving transistor DR may be a difference voltage (=ELVDD_(H)−|Vth|)between the first driving voltage ELVDD_(H) and the absolute value ofthe threshold voltage Vth, and the voltage V_(S) at the source of thedriving transistor DR may be the first driving voltage ELVDD_(H).

Therefore, in the second period F2, the threshold voltage Vth may besensed, and the data voltage Vdata may be charged into the gate of thedriving transistor DR.

Finally, as illustrated in FIGS. 12, 13, and 16, in a third period F3,the transparent area gate signals TGS having a high level may besupplied to the transparent area gate lines TGL. The transparent areagate signals TGS having a high level may be supplied to the gates of thefirst transistors SW1 included in the first pixel driving circuits PDC1.Therefore, the first transistors SW1 may be turned off. The supply ofthe transparent area gate signals TGS having a high level to thetransparent area gate lines TGL may denote that the secondinitialization transistor Tini2 illustrated in FIG. 11 are turned on bythe second turn-on control signal EN_SN, and thus, the gate-off signalVoff having a high level is supplied to the transparent area gate lineTGL.

In this case, the first driving voltage ELVDD may have a high level.That is, the first driving voltage ELVDD_(H) supplied to the transparentarea AA1 may have a low level in the first period F1 and may have a highlevel in the third period F3. Therefore, a switch for transferring thefirst driving voltage ELVDD should be provided. The switch may beincluded in the power supply 700, and in a case where the first drivingvoltage ELVDD_(H) is supplied through the gate driver 200, the switchmay be included in the gate driver 200. A control signal for turning onthe switch may be generated by the controller 400 and may be supplied tothe switch. However, the first driving voltage ELVDD_(H) having acertain level may be supplied to the opaque area AA2.

The data control signal DATA_EN may have a high level and the emissionsignal EM may have a low level, and thus, the data voltage controltransistor Tdc may be turned off and the reference voltage controltransistor Trc may be turned on. Therefore, the reference voltageVREF_(L) having a low level may be supplied to the first terminal of thecapacitor CST.

Since the emission signal EM has a high level, the second transistor SW2may be turned on.

Therefore, the voltage (=ELVDD_(H)−|Vth|−Vdata) calculated bysubtracting the absolute value of the threshold voltage Vth of thedriving transistor DR and the data voltage Vdata from the first drivingvoltage ELVDD_(H) may be charged into the capacitor CST, the voltage VGat the gate of the driving transistor DR may be a voltage(=ELVDD_(H)−|Vth|−Vdata+VREF_(L)) calculated by subtracting the absolutevalue of the threshold voltage Vth of the driving transistor DR and thedata voltage Vdata from a sum of the first driving voltage ELVDD_(H) andthe reference voltage VREF_(L), and the voltage V_(S) at the source ofthe driving transistor DR may be the first driving voltage ELVDD_(H).

In this case, a current I_(OLED) flowing to the first organic lightemitting diode OLED1 through the driving transistor DR may be expressedas the following Equation 1. In Equation 1, a may be a proportionalconstant.

$\begin{matrix}{I_{OLED} = {{a\left( {V_{SG} - {V_{TH}}} \right)}^{2} = {a\left( {{Vdata} - {VREF}_{L}} \right)}^{2}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

That is, in the third period F3, the current I_(OLED) flowing to thefirst organic light emitting diode OLED1 may be based on the datavoltage Vdata and the reference voltage VREF_(L) and may not be affectedby a shift of the threshold voltage Vth of the driving transistor DR.

Therefore, even when the threshold voltage Vth of the driving transistorDR is shifted because the driving transistor DR is used for a long time,the current I_(OLED) flowing to the first organic light emitting diodeOLED1 may not be affected by a shift of the threshold voltage Vth of thedriving transistor DR.

That is, according to the present disclosure described above, the firstpixel 110 a and the second pixel 110 b may output light based on thedata voltage Vdata without being affected by a shift of the thresholdvoltage Vth.

FIG. 17 is another exemplary diagram illustrating a first pixel and asecond pixel each included in an organic light emitting displayapparatus according to an embodiment of the present disclosure, and FIG.18 is an exemplary diagram illustrating a gate driver, an initializationunit, and a transparent area each applied to the organic light emittingdisplay apparatus illustrated in FIG. 17. In FIG. 18, gate pulsessupplied to the first pixel 110 a and the second pixel 110 b areillustrated. In the following description, descriptions which are thesame as or similar to descriptions given above with reference to FIGS. 1to 16 are omitted or will be briefly given.

As described above, the organic light emitting display apparatusaccording to an embodiment of the present disclosure may include theorganic light emitting display panel 100 including the first pixels 110a and the second pixels 110 b, the gate driver 200, the data driver 300,the initialization unit 500, and the controller 400.

The transparent area AA1, as illustrated in FIGS. 2 and 5, may be formedfrom one end of the display area AA to the other end of the display areaAA.

In this case, the initialization unit 500 may be provided in the firstnon-display area NAA1 along with the gate driver 200, or may be includedin the gate driver 200. When the initialization unit 500 is separatedfrom the gate driver 200, the initialization unit 500 may be providedbetween the gate driver 200 and the transparent area AA1.

Moreover, as illustrated in FIGS. 1, 17, and 18, the transparent areaAA1 may be surrounded by the opaque area AA2. That is, the transparentarea AA1 may be formed in only a region, corresponding to a region wherethe camera 600 is disposed in the organic light emitting displayapparatus, of the organic light emitting display panel 100.

In this case, as illustrated in FIG. 18, the initialization unit 500 maybe provided in a boundary region between the transparent area AA1 and afirst opaque area AA2 a provided at one side of the transparent areaAA1. The initialization unit 500 may include a plurality of firstinitialization drivers 511 connected to the transparent area gate lines.The boundary region may be the first opaque area AA2 a, or may be thetransparent area AA1. For example, the initialization unit 500 may beprovided in the second pixels 110 b provided in the first opaque areaAA2 a, provided in the first pixels 110 a provided in the transparentarea AA1, or provided in the first pixels 110 a and the second pixels110 b.

A configuration and a function of the initialization unit 500 may be thesame as those of the initialization unit 500 described above withreference to FIGS. 9 to 12.

Therefore, a configuration and a function of the first initializationdriver 511 illustrated in FIG. 18 may be the same as those of the firstinitialization driver 510 described above with reference to FIGS. 9 and11.

That is, as illustrated in FIG. 11, each of the first initializationdrivers 511 illustrated in FIG. 18 may include a first initializationtransistor Tini1, which includes a first terminal connected to aninitialization control signal supply line ISL, a second terminalconnected to the transparent area gate line TGL, and a gate connected toa first turn-on control line TCL1, and a second initializationtransistor Tini2 which includes a first terminal connected to an opaquearea gate line GL extending from the gate driver 200 to the first opaquearea AA2 a among the gate lines, a second terminal connected to thetransparent area gate line, and a gate connected to a second turn-oncontrol line TCL2.

In this case, a difference between the first initialization driver 511illustrated in FIG. 18 and the first initialization driver 510 describedabove with reference to FIGS. 9 and 11 may be that the first terminal ofthe second initialization transistor Tini2 is connected to the opaquearea gate line GL extending from the gate driver 200 to the first opaquearea AA2 a among the gate lines.

That is, the initialization unit 500 described above with reference toFIGS. 9 and 11 may be directly connected to the gate driver 200, but theinitialization unit 500 described above with reference to FIG. 18 may beconnected to the gate driver 200 through the first opaque area AA2 a.

Therefore, the first terminal of the second initialization transistorTini2 illustrated in FIG. 18 may be connected to the gate driver 200through the opaque area gate line GL extending from the gate driver 200to the first opaque area AA2 a among the gate lines.

Except for a structural difference described above, a configuration anda function of the first initialization driver 511 illustrated in FIG. 18may be the same as those of the first initialization driver 510illustrated in FIGS. 9 and 11.

In this case, each of the first initialization drivers 511 illustratedin FIG. 18 may transfer gate pulses SCANg-3 to SCANg, which are outputfrom the gate driver 200 and pass through the first opaque area AA2A, totransparent area gate lines TGL provided in the transparent area AA1among the plurality of gate lines, or may transfer, to the transparentarea gate lines TGL, initialization control signals VGL for initializingthe first pixel driving circuits provided in the transparent area AA1.

In this case, as illustrated in FIG. 18, the initialization unit 500 mayfurther include a plurality of second initialization drivers 512.

For example, the second initialization drivers 512 may be provided in aboundary region between the transparent area AA1 and a second opaquearea AA2 b provided at the other side of the transparent area AA1. Also,the second initialization drivers 512 may be connected to thetransparent area gate lines and a plurality of opaque area gate linesprovided in the second opaque area AA2 b.

That is, the second initialization drivers 512 may be provided to besymmetrical with the first initialization drivers 511 with thetransparent areas AA1 therebetween.

Therefore, a configuration, a function, and a driving method of each ofthe second initialization drivers 512 may be the same as those of eachof the first initialization drivers 511.

In the organic light emitting display apparatus, as illustrated in FIG.18, the gate driver 200 may include a first driver 210, provided at theone side (i.e., the first non-display area NAA1) of the transparent areaAA1 in the non-display area NAA, and a second driver 220 provided at theother side (i.e., the second non-display area NAA2) of the transparentarea AA1 in the non-display area NAA.

The first driver 210 and the second driver 220 may simultaneously outputgate pulses to the same gate lines, or may output the gate pulses todifferent gate lines.

In this case, the initialization unit 500 (particularly, the firstinitialization driver 510 included in the initialization unit 500) maysupply a gate pulse, supplied through the first opaque area AA2 a fromthe first driver 210, to the transparent area gate line TGL.

The second driver 220 may supply a gate pulse to the second opaque areaAA2 b provided at the other side NAA2 of the transparent area AA1. Thesecond initialization drivers 512 may supply gate pulses, transferredthrough the second opaque area AA2 b from the second driver 220, to thetransparent area gate lines TGL provided in the transparent area AA1.

However, the second initialization drivers 512 may be omitted. In thiscase, gate pulses supplied from the second driver 220 may be supplied toonly opaque area gate lines provided in the second opaque area AA2 b.That is, the opaque area gate lines provided in the second opaque areaAA2 b may not be connected to the transparent area gate lines.

FIGS. 19A and 19B are exemplary diagrams illustrating a result obtainedby comparing the compensation performance of a related art pixel drivingcircuit with the compensation performance of a first pixel drivingcircuit applied to an organic light emitting display apparatus accordingto an embodiment of the present disclosure. Particularly, FIG. 19Aillustrates internal compensation performance based on the first pixeldriving circuit PDC1 having a structure illustrated in FIG. 6, and FIG.19B illustrates internal compensation performance based on the secondpixel driving circuit PDC2 including seven transistors and onecapacitor.

In the present disclosure, as described above, the first pixel 110 aprovided in the transparent area AA1 may include, for example, aninternal compensation circuit (i.e., the first pixel driving circuitPDC1) including three transistors and one capacitor, and the secondpixel 110 b provided in the opaque area AA2 may include, for example, atleast four capacitors.

In this case, particularly, FIGS. 19A and 19B illustrate a resultobtained by comparing the compensation performance of the second pixel110 b, which includes seven transistors and one capacitor and performsinternal compensation, with the compensation performance of the firstpixel 110 a which includes three transistors and one capacitor andperforms internal compensation.

That is, in a low gray level such as 31 gray and 64 gray, compensationperformance based on the first pixel driving circuit PDC1 maintains thesame level as compensation performance based on the second pixel drivingcircuit PDC2, but in 255 gray, compensation performance based on thefirst pixel driving circuit PDC1 maintains a level which is higher thancompensation performance based on the second pixel driving circuit PDC2.

Therefore, it may be seen that the compensation performance of the firstpixel driving circuit PDC1 is similar to that of the second pixeldriving circuit PDC2, and thus, there is no an image quality differencebetween the transparent area and the opaque area.

Features of the present disclosure described above will be brieflydescribed.

In the present disclosure, for example, an internal compensation circuit(i.e., the first pixel driving circuit PDC1) including three PMOStransistors and one capacitor may be included in each of the firstpixels 110 a provided in the transparent area AA1, and an internalcompensation circuit (i.e., the second pixel driving circuit PDC2)including four or more transistors and one or more capacitors may beincluded in each of the second pixels 110 b provided in the opaque areaAA2.

Therefore, a light transmittance of the transparent area may be higherthan that of the opaque area.

The transparent area AA1 may correspond to a position of a cameradisposed at the rear surface of the organic light emitting display panel100 to face a region in front of the organic light emitting displaypanel 100.

A density (PPI) of pixels provided in the transparent area AA1 may beset to be equal to a density (PPI) of pixels provided in the opaque areaAA2. Therefore, comparing with a related art organic light emittingdisplay apparatus where a PPI of the transparent area is set to be lowerthan a PPI of the opaque area, the degradation in image quality may beminimized in the present disclosure. Accordingly, even when a camera isdisposed at the rear surface of the organic light emitting displaypanel, photographing may be performed.

For example, in order to place the camera 600 and other sensors, asillustrated in FIG. 5, all regions corresponding to about 3 mm of anupper end (about 64 lines with respect to 537 ppi) of the organic lightemitting display panel 100 may be formed as the transparent area AA1.

Moreover, as illustrated in FIG. 17, only a region corresponding to thecamera 600 among regions corresponding to about 3 mm of the upper end ofthe organic light emitting display panel 100 may be the transparent areaAA1. That is, only a region (about 3×3 mm, 537 ppi reference resolution64×64), corresponding to the camera 600, of the organic light emittingdisplay panel 100 may be the transparent area AA1.

An anode of the first organic light emitting diode OLED1 provided in thetransparent area AA1 may be formed of a transparent electrode and areflective electrode, but may be formed of only transparent metal, forincreasing a transmittance.

In addition to the anode, all lines provided in the transparent area AA1may be formed of transparent metal, for maximizing a transmittance ofthe transparent area AA1.

In the present disclosure, all first pixel driving circuits PDC1provided in the transparent area AA1 may be simultaneously initialized,a threshold voltage may be compensated for by line units, data voltagesmay be recorded in all first pixels, and all lines may simultaneouslyemit light.

In the present disclosure, gate pulses output from the gate driver 200may not differ from the related art. Therefore, a structure of the gatedriver 200 may use a gate driver applied to a related art organic lightemitting display apparatus.

In order to enhance a transmittance, as illustrated in FIG. 12, thefirst pixels 110 a provided in the transparent area AA1 may usetransparent metal such as ITO instead of a metal line (for example,titanium/aluminum/titanium (Ti/Al/Ti)) of the related art, andparticularly, a reflective electrode (Ag) of an anode may be omitted forenhancing a transmittance.

In the present disclosure, the first pixel driving circuit PDC1 having aPMOS 3T1C structure occupying a smaller area than the second pixeldriving circuit PDC2 may be provided in the transparent area AA1,thereby minimizing the degradation in image quality of the camera 600facing a region in front of the organic light emitting display panel100. However, the first pixel driving circuit PDC1 is not limited toincluding three transistors and one capacitor. That is, the first pixeldriving circuit PDC1 may be variously provided as a number which is lessthan the number of transistors included in a related art internalcompensation circuit, and particularly, the number of transistorsincluded in the first pixel driving circuit PDC1 may be variously set tobe less than the number of transistors included in the second pixeldriving circuit PDC2. Accordingly, according to the present disclosure,an organic light emitting display panel having a high-transmittancetransparent area may be provided.

According to the present disclosure, even without a notch or a hole, afull display may be implemented for photographing a region in front ofan organic light emitting display panel.

In the present disclosure, the PMOS 3T1C structure may use a globalshutter driving manner, but such a structure is applied to only somelines corresponding to a camera region (i.e., the transparent area AA1).Therefore, according to the present disclosure, a non-emission time forwhich a data voltage is recorded may be short, and thus, a highluminance of 600 nit or more may be implemented.

In the present disclosure, one organic light emitting display panel mayinclude a transparent area, including an internal compensation circuithaving the PMOS 3T1C structure, and an opaque area where an internalcompensation circuit including four or more transistors is provided.

In the present disclosure, the transparent area including the internalcompensation circuit having the PMOS 3T1C structure may be provided at awhole upper end line of the organic light emitting display panel, or maybe provided in only a region corresponding to a camera. In this case,signals for controlling an internal compensation circuit (i.e., thefirst pixel driving circuit PDC1) provided in the transparent area maybe supplied to the first pixel driving circuit PDC1 by theinitialization unit 500.

In the present disclosure, various lines provided in the transparentarea may use transparent metal, but may use opaque metal which is beingused currently and widely, for improving IR-drop.

In the present disclosure, the anode provided in the transparent areamay be formed of only transparent metal such as ITO, for enhancing atransmittance, but in order to enhance emission efficiency although atransmittance is reduced, the anode may be formed of transparent metal(ITO) and opaque metal (Ag) or an alloy thereof.

In an organic light emitting display apparatus according to theembodiments of the present disclosure, a first pixel driving circuitprovided in a transparent area, corresponding to a position of a camera,of a display area displaying an image may have a shape differing fromthat of a second pixel driving circuit provided in an opaque area,except the transparent area, of the display area, and particularly, thenumber of transistors included in the first pixel driving circuit may beless than the number of transistors included in the second pixel drivingcircuit.

Therefore, the amount of light transferred to the camera through thetransparent area may increase, and thus, the quality of an imagecaptured by the camera may be enhanced.

That is, according to the embodiments of the present disclosure, atransparent pixel structure (a PMOS 3T1C internal compensation circuit)may be applied to a region, where a front camera is disposed, of theorganic light emitting display panel, and thus, even when a camera isdisposed on a rear surface of the organic light emitting display panel,photographing may be performed. Particularly, according to theembodiments of the present disclosure, pixels of the transparent areamay be implemented at the same density (PPI) as pixels of a related artorganic light emitting display panel, and thus, the reduction in imagequality may decrease compared to the related art organic light emittingdisplay panel where the pixels of the transparent area are implementedat a low density (PPI).

The above-described feature, structure, and effect of the presentdisclosure are included in at least one embodiment of the presentdisclosure, but are not limited to only one embodiment. Furthermore, thefeature, structure, and effect described in at least one embodiment ofthe present disclosure may be implemented through combination ormodification of other embodiments by those skilled in the art.Therefore, content associated with the combination and modificationshould be construed as being within the scope of the present disclosure.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present disclosurewithout departing from the spirit or scope of the disclosures. Thus, itis intended that the present disclosure covers the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

1. An organic light emitting display apparatus, comprising: an organiclight emitting display panel including a display area having atransparent area and an opaque area, and a non-display area; a gatedriver configured to sequentially supply a gate pulse to a plurality ofgate lines included in the organic light emitting display panel; aninitialization circuit configured to transfer gate pulses orinitialization control signals, output from the gate driver, to aplurality of transparent area gate lines; a camera configured tophotograph a region in a forward direction with respect to the organiclight emitting display panel, the camera provided in the transparentarea of a rear surface of the organic light emitting display panel; anda plurality of first pixel driving circuits provided in the transparentarea, and a plurality of second pixel driving circuits provided in theopaque area, wherein the first pixel driving circuit differs from thesecond pixel driving circuit.
 2. The organic light emitting displayapparatus of claim 1, wherein the organic light emitting display panelincludes: a plurality of first pixels provided in the transparent area,each of the first pixels including a respective first pixel drivingcircuit of the plurality of first pixel driving circuits and a firstorganic light emitting diode connected to the first pixel drivingcircuit, and a plurality of second pixels provided in the opaque area,each of the second pixels including a respective second pixel drivingcircuit of the plurality of second driving circuits and a second organiclight emitting diode connected to the second pixel driving circuit. 3.The organic light emitting display apparatus of claim 1, wherein: theinitialization circuit comprises a plurality of first initializationdrivers connected to the plurality of transparent area gate lines, andeach of the plurality of first initialization drivers comprises: a firstinitialization transistor including a first terminal connected to aninitialization control signal supply line, a second terminal connectedto a transparent area gate line, and a gate connected to a first turn-oncontrol line; and a second initialization transistor including a firstterminal connected to a transparent area gate output line of the gatedriver, a second terminal connected to the transparent area gate line,and a gate connected to a second turn-on control line.
 4. The organiclight emitting display apparatus of claim 3, wherein a phase of a firstturn-on control signal supplied through the first turn-on control lineis opposite to a phase of a second turn-on control signal suppliedthrough the second turn-on control line.
 5. The organic light emittingdisplay apparatus of claim 1, wherein each of the first pixel drivingcircuits comprises: a capacitor including a first terminal connected toa transfer line through which a reference voltage or a data voltage istransferred; a driving transistor including a first terminal connectedto a first driving voltage line and a gate connected to a secondterminal of the capacitor; a first transistor including a first terminalconnected to the gate of the driving transistor, a second terminalconnected to a second terminal of the driving transistor, and a gateconnected to the transparent area gate line; and a second transistorincluding a first terminal connected to the second terminal of thedriving transistor, a second terminal connected to the first organiclight emitting diode, and a gate connected to an emission control line.6. The organic light emitting display apparatus of claim 1, wherein thetransparent area extends from a first end of the display area to asecond end of the display area that is opposite the first end.
 7. Theorganic light emitting display apparatus of claim 1, wherein thetransparent area is laterally surrounded by the opaque area.
 8. Theorganic light emitting display apparatus of claim 7, wherein: theinitialization circuit comprises a plurality of first initializationdrivers, and each of the plurality of first initialization drivers isprovided in a boundary region between the transparent area and a firstopaque area provided at a first side of the transparent area and isconnected to the plurality of transparent area gate lines.
 9. Theorganic light emitting display apparatus of claim 8, wherein each of theplurality of first initialization drivers comprises: a firstinitialization transistor including a first terminal connected to aninitialization control signal supply line, a second terminal connectedto the transparent area gate line, and a gate connected to a firstturn-on control line; and a second initialization transistor including afirst terminal connected to an opaque area gate line extending from thegate driver to the first opaque area among the plurality of gate lines,a second terminal connected to the transparent area gate line, and agate connected to a second turn-on control line.
 10. The organic lightemitting display apparatus of claim 8, wherein the gate drivercomprises: a first driver provided at the first side of the transparentarea in the non-display area; a second driver provided at a second sideof the transparent area in the non-display area; the initialization unitsupplies the plurality of transparent area gate lines with a gate pulsesupplied through the first opaque area from the first driver; and thesecond driver supplies a gate pulse to a second opaque area provided atthe second side of the transparent area.
 11. The organic light emittingdisplay apparatus of claim 10, wherein the initialization circuitfurther comprises a plurality of second initialization drivers providedin a boundary region between the transparent area and the second opaquearea and connected to the plurality of transparent area gate lines. 12.The organic light emitting display apparatus of claim 1, wherein adensity of a plurality of first pixels of the transparent area is thesame as a density of a plurality of pixels of the opaque area.
 13. Theorganic light emitting display apparatus of claim 5, wherein a firstterminal of the capacitor is connected to a reference voltage controltransistor and a data voltage control transistor, a first terminal ofthe reference voltage control transistor is connected to a referencevoltage supply line through which a reference voltage is supplied, asecond terminal thereof is connected to the first terminal of thecapacitor, and a gate thereof is connected to an emission line throughwhich an emission signal is supplied, and a first terminal of the datavoltage control transistor is connected to the first terminal of thecapacitor, a second terminal thereof is connected to the data driver,and a gate thereof is connected to a data control line through which adata control signal is supplied.
 14. The organic light emitting displayapparatus of claim 13, wherein a data extension line provided betweenthe second terminal of the reference voltage control transistor and thefirst terminal of the data voltage control transistor is connected to aplurality of transfer lines which are connected to a plurality of firstpixels provided along the data extension line, and a data line providedbetween the data voltage control transistor and the data driver isconnected to a plurality of opaque area gate lines which are connectedto a plurality of second pixels provided along the data line.
 15. Theorganic light emitting display apparatus of claim 11, wherein theplurality of second initialization drivers supply the plurality oftransparent area gate lines with gate pulses transferred from the seconddriver through a plurality of opaque area gate lines provided in theopaque area.
 16. The organic light emitting display apparatus of claim11, wherein each of the plurality of second initialization driverscomprises: a first initialization transistor including a first terminalconnected to an initialization control signal supply line, a secondterminal connected to a transparent area gate line, and a gate connectedto a first turn-on control line; and a second initialization transistorincluding a first terminal connected to a transparent area gate outputline of the gate driver, a second terminal connected to the transparentarea gate line, and a gate connected to a second turn-on control line.17. The organic light emitting display apparatus of claim 5, whereineach of the second pixel driving circuits comprises at least fourtransistors.
 18. The organic light emitting display apparatus of claim5, wherein each of the first pixel driving circuits comprises threetransistors.
 19. The organic light emitting display apparatus of claim1, wherein a number of transistors included in each of the first pixeldriving circuits is less than number of transistors included in each ofthe second pixel driving circuits.